Bump actions/stale from 5 to 6

Bumps [actions/stale](https://github.com/actions/stale) from 5 to 6.
- [Release notes](https://github.com/actions/stale/releases)
- [Changelog](https://github.com/actions/stale/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/stale/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/stale
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/issues-stale.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Stale
-        uses: actions/stale@v5
+        uses: actions/stale@v6
         with:
           stale-issue-message: >
             This issue is stale because it has been open for 30 days with no activity.
@@ -30,7 +30,7 @@ jobs:
           days-before-close: 5
 
       - name: Invalid Template
-        uses: actions/stale@v5
+        uses: actions/stale@v6
         with:
           stale-issue-message: >
             Invalid issues template.